1-thiadiazolyl-3-alkyl-5-alkoxyimidazolidinones

ABSTRACT

This invention discloses compounds of the formula   alkylsulfi wherein R1 is selected from the group consisting of alkyl, alkenyl, chloroalkyl, trifluoromethyl, alkoxy, alkylthio, alkylsulfonyl, alkylsulfinyl and cycloalkyl of from 3 to 7 carbon atoms optionally substituted with from 1 to 2 substituents selected from the group consisting of alkyl, alkoxy and halogen; and R2 and R3 are each alkyl. Further disclosed are herbicidal compositions containing a compound of the above description.

United States Patent 1 Primary Examiner-Richard J. Gallagher Attorney,Agent, or Firm-Robert J. Schwarz; Dietmar H. Olesch ,Krenzer 1*Aug. 26,1975 l-THlADIAZOLYL-3ALKYL 5- [57] ABSTRACT ALKOXYIMIDAZOUDINONES Thisinvention discloses compounds of the formula [75] Inventor: JohnKrenzer, Oak'Park,.lll.

[73] Assignee: Velsicol Chemical Corporation, 0R3

Chicago, Ill. I

N N t. H H; Notice: The portion of the term of this R l l N N R2 patentsubsequent to Aug. 26, 1992, has been disclaimed. s [22] Filed: Mar. 18,1974 0 211 Appl. No.: 452,021

wherein R is selected from the group consisting of alkyl, alkenyl,chloroalkyl, trifluoromethyl, alkoxy, al-

83 2 3 132 kylthio, alkylsulfonyl, alkylsulfinyl and cycloalkyl of o o aa l v I u s 1 f 3 t 7 t t b t't t d 'th 58 Field of Search 260/3068 1)mm car a 0m y S u e from 1 to 2 substituents selected from the groupconsisting of alkyl, alkoxy and halogen; and R and R are each alkyl.Further disclosed are herbicidal compositions containing a compound ofthe above description.

6 Claims, No Drawings formula wherein R isselected from the groupconsisting of alkyl, alkenyl, chloroalkyl, trifluoromethyl, alkoxy,alk-ylthio, alkylsulfonyl, alkylsulfinyl and cycloalkyl of from 3 to 7carbon atoms optionally substituted with from 1 to 2 substituentsselected from the group consisting of alkyl, alkoxy and halogen; and Rand R are each alkyl.

The compounds of the present invention are unexpectedly useful asherbicides.

In a preferred embodiment of this invention R is selected from the groupconsisting of lower alkyl, lower alkenyl, lower chloroalkyl,trifluoromethyl, lower alkoxy, lower alkylthio, lower alkylsulfonyl,lower alkylsulfinyl and cycloalkyl of from 3 to 7. carbon atoms.optionally substituted with from 1 to 2 substituents selected from thegroupv consisting of lower alkyl, lower alkoxy chlorine, bromine andfluorine; R is lower alkyl; and R? is an alkyl group of up to twentycarbon atoms,

The term lower as used herein designates a straight or branched carbonchain of up-to six carbon atoms.

The compounds of-this invention can be prepared by reacting a compoundof the formula wherein R and R are as heretofore defined, with analcohol of the formula lll wherein R is asheretofore.described.Thisreaction can be effected by combining thecompound offormula ll with an excess molar amount of the alcohol offormula ill in the presence of a catalytic amount of toluenesulfonicacid and heating the reaction mixture at a temperature of from about Cto about the reflux temperature of the mixture for a period of fromabout 6 to about 24 hours. After this time the reaction mixture can bestrippedof excess alcohol under reduced pressure to yield the desiredproduct as the residue. This product can then be usedas such or can befurther purified by conventional techniques such as recrystallizationand'the like. i

The compounds of formula II can be readily prepared by heating acompound of the formula 'ocH, (IV) wherein R and R are as heretoforedescribed, in a dilute, aqueous, acidic reaction medium for a period ofabout 10 to about 60 minutes. Temperatures of from about C to the refluxtemperature of the reaction mixturecanbe utilized. The reaction mediumcan comprise a dilute aqueous inorganic acid such as hydrochlorieacid ata concentration of from about 0.5 to about 5- percent. Upon completionof the reaction the desired product can be recovered as a precipitate bycooling'the reaction mixture. This product can be used' as such or canbe further purified by conventional means such as recrystallization andthe like.

' The compounds of formula IV can be prepared by reacting a molar amountof an isocyanate dimer of the formula wherein R is as heretoforedescribed, withabout two molar amounts of a dimethyl acetal of theformula ('XH H i 1 CH. ,-clH

R OCH (VI) wherein R ,is as heretofore described. This reaction can beeffected by heating a mixture of the isocyanate dimer and the acetal inan inert organic reaction medium such as benzene at the refluxtemperature of the reaction mixture. Heating at reflux can be continuedfor a period of from about 2 to about 30 minutes to ensure completion ofthe reaction. After this time the desired product can be recovered uponevaporation of the reaction medium and can be used as such or can befurther purified by standardtechniques in the art.

The isocyanate dimer of formula V can be prepared by reacting athiadiazole of the formula N N II II wherein R is as heretoforedescribed, with phosgene. This reaction can be effected by adding aslurry or solution of the thiadiazole, in a suitable organic solventlsuch as ethyl acetate,.to a saturated solution of phosthiadiazole.5-butylthio-2-amino-1,3.4-thiadiazolc, 5- methylsulfonyl-Z-amino-l ,3,4-thiadiazole, 5 ethylsulfonyl-Z-aminol ,3 ,4-thiadiazole. 5-butylsulfonyl-Lamino-l .3,4-thiadiazole, 5- methylsulfinyl-Z-amino-1,3.4-thiadiazole, 5- ethylsulfinyl-Z-amino-1,3.4-thiadiazole. 5-propylsulfinyl-2-aminol .3,4-thiadiazole. S-t-butyl-Z-amino-1,3.4-thiadiazole. 5-trifluoromethyl-2 -amino- 1,3 ,4-thiadiazole,5-cyelopropyl-2-amino-1.3 4- thiadiazole.5-cyclobutyl-2-amino'1.3.4-thiadiazolc. S-cyclopentyl-Z-amino-1,3,4-thiadiazole. 5-cyclohcxyl- 2-amino-l .3 .4-thiadiazole,5-cycloheptyl-2-amino- 1,3,4-thiadiazole, 5-( 2-methylcyclopropyl)-2-aminol,3.4-thiadiazole, 5-( 3-ethyleyclopentyl )-2-amino-1.3,4-thiadiazole, 1.3 ,4-thiadiazole. 1,3 .4-thiadiazole,113.4-thiadiazo1e, 1 ,3 ,4'-thiadiazole,

5-( l-methylcyclohexyl )-2-amino- 5-( 4-chlorocyclohexyl )-2-amino- 5-(4-bromocyclohexyl )-2-amino- 5-(4-fluorocyclohexyl)-2-amino 1,3,4-thiadiazole, 5-( 3-methoxycycloheptyl )-2-amino- 1.3,4-thiadiazole.5-( 3-hexylcyclopentyl )-2-amino- 1,3.4-thiadiazolc,5-(4-hexyloxycyclohexyl)-2-amino- 1,3 ,4-thiadiazole, 5-(4-iodocyelohexyl )-2-arnino-l .3 .4- thiadiazole and the like. i

- The manner in which the compounds of this invention can be prepared ismore specifically ill ustratedin the following examples.

EXAMPLE l Preparation of S-Trifluoromethyl-l,3,4-thiadiazol-2-yllsocyanate Dimer A saturated solution of phosgene in ethyl acetate (100ml) was charged into a glass reaction vessel equipped with a mechanicalstirrer. A slurry of 5- trifluoromethyl-Z-amino-1.3,4-thiadiazole (45grams) in ethyl acetate (300 ml) was added to the reaction vessel andthe resulting mixture was stirred for a period of about 16 hoursresulting in the formation of a precipitate. The reaction mixture wasthen purged with nitrogen gas to remove unreaeted phosgene. The purgedmixture was filtered to recover 48 grams of a white solid. This solidwas recrystallized from dimethyl formamide to yield the desired product5-trifluoromethyl- 1,3.4-thiadiazol-2-yl isocyanate dimer.

5-(4-propylcyclohexyl)-2-amino- EXAMPLE 2 Preparation of the DimethylAcetal of 2-[ l-Methy1-3 S-trifluoromethyl-l ,3,4-thiadiazol-2-yl)ureido]acetaldehyde A mixture ofS-trifluoromethyl-1,3,4-thiadiazol-2-yl isocyanate dimer (9.5 gram), thedimethyl acetal of 2- methylaminoacetaldehyde (5.8 grams) and benzene(60 ml) were charged into a glass reaction vessel equipped withamechanical stirrer and reflux condenser. The reaction mixture washeated at reflux for a period of about 15 minutes. After this time themixture was stripped of benzene under reduced pressure to yield a solidproduct as the residue. This product was recrystallized from heptane toyield the desired product the dimethyl acetal of 2-[ 1 -methyl-3-( 5-yl)ureido]acetaldehyde having .a melting point of 101 to 102C.

EXAMPLE13' Prepartion ofI-(S-Trifluoromethyl-1,3.4-thiadiazol-2-yl)-3-methyl- 5-hydroxy-1,3-imidazolidin-2-one The dimethyl acetal of 2-[l-methyl-3-(5-trifluoromethyl- 1 ,3.4-thiadiazol-2- yl)ureido1acetaldehyde 15 grams),water (400 ml) and hydrochloric acid (4 ml) were charged into a glassreactionvessel equipped with a mechanical stirrer, thermometer andreflux condenser. The reaction mixture was heated at reflux for a periodof about 15 minutes. The reaction mixture was then filtered while hotand the. filtratewas cooled resulting in the formation of a precipitate.The precipitate was recovered by filtration. was dried and wasrecrystallized from-an ethyl aeetatehexane mixture to yield the desiredproduct 1- (S-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-l,3-imidazolidin-2-one having a melting point of 136 to 138C.

EXAMPLE 4 Preparation of1-(5-Trifluoromethyl1.3,4-thiadiazol-2-yl)-3-methyl-S-methoxy-1.3rimidazolidin-2-one1-(5-Trifluoromethyl-1.3.4-thiadiazol-2-yl)-3- methyl-S-hydroxyl.3-imidazolidin-2-one (7 grams). methyl alcohol (50 ml) andtolucnesulfonic acid (0.2 grams) are charged into a glass reactionvessel equipped with a mechanical stirrer, thermometer and refluxcondenser. The reaction mixture is then heated at reflux for a period ofabout 24 hours. After this time the mixture is stripped of unreactedalcohol under reduced pressure to yield a solid product. The solidprodnet is then recrystallized to yield the desired product 1-(5-triflu'oromethyll ,3.4- thiadiazol-2-yl )-3-methyl-5- methoxy-1,3imidazolidin-2-one.

EXAMPLE 5 hours resulting in .the formation of a precipitate. Thereaction mixture was then purged with nitrogen gas to remove unreactedphosgene. The purged mixture was then filtered to recover the desiredproduct S-t-butyl- 1,3,4-thiadiazol-2-yl isocyanate dimer as a solidhaving a melting point of 261 to' 263C.

EXAMPLE 6 Preparation of the Dimethyl Acetal of 2-[ 1-methyl-3-(5-t-butyll ,3 ,4-thiadiazol-2- yl )ureido acetaldehyde A mixture ofS-t-butyl-l,3,4-thiadiazol-2-yl isocyanate dimer (6 grams), the dimethylacetal of 2- methylaminoacetaldehyde (3.9 grams) and benzene (50 ml) wascharged into a glass reaction flask equipped with a mechanical stirrerand reflux condenser. The reaction mixture was heated at reflux, withstirring for a period of about 5 minutes. After this time the reactionmixture was stripped of benzene to yield an oil which solidified uponstanding. The resulting solid was then recrystallized from pentane toyield the desired product the dimethyl acetal of 2-[ l-methyl- 3-(S-t-butyll ,3,4-thiadiazol-2-yl)ureido] acetaldehyde having a meltingpoint of 80 to 82C.

' EXAMPLE 7 Preparation of l-( 5-t-Butyll ,3 ,4-thiadiazol-2-yl)-3-methyl-5- hydroxy-l ,3-imidazolidin-2-one The dimethyl acetal of2-[1-ethyl-3-(5-methoxy-1,3,- 4-thiadiazol-2-yl)ureido] acetaldehyde (15grams), concentrated hydrochloric acid ml) and water (500 ml) werecharged into a glass reaction vessel equipped with a mechanical stirrer,thermometer and reflux condenser. The reaction mixture was heated atreflux for a period of about minutes. The reaction mixture was filteredwhile hot and the filtrate was then cooled, resulting in the formationof a precipitate. The precipitate was recovered by filtration, dried andwas recrystallized from a benzene-hexane mixture to yield the desiredproduct l-(5-t-butyl-l,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-l,3-imidazolidin-2-one having a melting point of 133to 134C.

EXAMPLE 8 Preparation of 1-( S-t-Butyll ,3,4-thiadiazol-2-yl)-3-methyl-5- methoxy-1,3-imidazolidin-2-one l-(S-t-Butyll ,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-l,3-imidazolidin-2-one (7 grams), methyl alcohol (50 ml) andtoluenesulfonic acid (0.2 grams) were charged into a glass reactionvessel equipped with a mechanical stirrer, thermometer and refluxcondenser. The reaction mixture was then heated at reflux for a periodof about 24 hours. After this time the mixture was stripped of alcoholunder reduced pressure leaving a solid residue. The residue wasdissolved in heptane 100 ml) and the heptane solution was filteredthrough diatomaceous earth. The filteredsolution was then cooled in anice bath resulting in the precipitation of a crystalline product. Theproductwas'recovered by filtration and dried under vacuum to yield'thedesired product l-( S-t-butyll ,3 ,4-thiadiazol-2-yl )-3-methyl-5-methoxy-1,3-imidazolidin-2-one having a melting point of 73 to 76C.

' EXAMPLE 9 Preparation of'5-Methy1-l,3,4-thiadiazol-2-yl IsocyanateDimer A saturated solution of phosgene in ethyl acetate ml) is chargedinto a glass reaction vessel equipped with a mechanical stirrer. Aslurry of 5- methyl-2-amino-1,3,4-thiadiazole (40 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product5-methyl-l,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 10 Preparation of the Dimethyl Acetal of 2-[ 1-Methyl-3-(S-methyll ,3,4-thiadiazol-2- yl)ureido]acetaldehyde EXAMPLE 1 1Preparation of l-( S-Methyll ,3 ,4-thiadiazol-2-yl)-3-methyl-5- hydroxyl,3-imidazolidin-2-one The dimethyl acetal of 2-[l-methyl-3-(5-methyll,3,4-thiadiazol-2-yl)ureido]acetaldehyde l5 grams),water (400 ml) and hydrochloric acid (4 ml) are charged into aglassfreaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product l-(5- methyl- 1,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxyl ,3- imidazolidin-Z-one.

EXAMPLE l2 Preparation of v l-( 5-Methyll ,3 ,4-thiadiazol-2-yl)-3-methyl-5-ethoxy- 1,3-imidazolidin-2-one l-( S-Methyll ,3,4-thiadiazol-2-yl )-3-methyl-5- hydroxy-l,3-imidazolidin-2-one (7grams), ethyl alcohol (50 ml) and toluenesulfonic acid (0.2 grams) arecharged into a glass reaction vessel equipped with a mechanical stirrer,thermometer and reflux condenser.

The reaction mixture is then heated at reflux for a period of about 24hours. After this time the mixture is stripped of unreacted alcoholunder reduced pressure to yield a solid product. The solid product isthen recrystallized to yield the desired product l-(5-methyl- 7 1,3,4-thiadiazol-2-yl)-3-methyl-5-ethoxy-1,3- imidazolidin-2-one.

EXAMPLE 13 Preparation of S-Methoxy-l ,3 ,4-thiadiazol-2-yl lsocyanateDimer A saturated solution of phosgene in ethyl acetate (100 ml) ischarged into a glass reaction vessel v l,3-im idazolidin 2 -olne,

equipped with a mechanical stirrer. A slurry of 5- Omethoxy-2-amino-1.3,4-thiadiazole (40 grams) in ethyl acetate (300 ml)is added to the reaction vessel and the resulting mixture is stirred fora period of about 16 hours, resulting in the formation of a precipitate.The reaction mixture is then purged with nitrogen gas to re- 'moveunreacted phosgene. The purged mixture is then filtered to recover theprecipitate. The precipitate is then recrystallized to yield the desiredproduct 5- methoxy-l ,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 14 Preparation of the Dimethyl Acetal of 2-[ l-Ethyl-3-(S-methoxyl ,3 ,4-thiadiazol-2- yl)ureido]acetaldehyde A mixture ofS-methoxy-l,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole), thedimethyl acetal of 2- ethylaminoacetaldehyde (0.1 mole) and benzene (60ml) are charged into a glass reaction vessel equipped with a mechanicalstirrer and reflux condenser. The reaction mixture is heated at refluxfor a period of about 15 minutes. After this time the mixture isstripped of benzene under reduced pressure to yield a solid product asthe residue. The residue is then recrystallized to yield the desiredproduct the dimethyl acetal of 2-[1- ethyl-3-( S-methoxy-l ,3,4-thiadiazol-2- yl)ureido]acetaldehyde.

EXAMPLE l5 Preparation of 1-( S-Methoxyl ,3 ,4-thiadiazol-2-yl)-3-ethyl-5- hydroxyl ,3-imidazolidin-2-one The dimethyl acetal of2-[1-ethyl-3-(5 -methoxy- 1,3

4-thiadiazol-2-yl)ureido]acetaldehyde (15 grains), water (400 ml) andhydrochloric acid (4 ml) are charged into a glass reaction vesselequipped with a mechanical stirrer, thermometer and reflux condenser.The reaction mixture is heated at reflux for a period of about 15minutes. The reaction mixture is then filtered while hot and thefiltrate is cooled to form a precipitate. The precipitate is recoveredby filtration, is dried and is recrystallized to yield the desiredproduct l-(5- methoxy- 1 ,3,4-thiadiazol-2-yl )-3-ethyl-5-hydroxyl ,3-

1 imidazolidin-Z-one.

EXAMPLE 16 Preparation of l-( 5-Methoxyl ,3,4-thiadiazol-2-yl)-3-ethyl-5-npropoxy-l ,3-imidazolidin-2-one1-(5-Methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-hydroxy-l,3-imidazolidin-2-one (7 grams), n-propyl alcohol (50 ml) andtoluenesulfonic acid (0.2 grams) are charged into a glass reactionvessel equipped with a mechanical stirrer, thermometer and refluxcondenser. The reaction mixture is then heated at reflux for a period ofabout 24 hours. After this time the mixture is stripped of unreactedalcohol under reduced pressure to yield a solid product. The solidproduct is 8 then recrystallized to yield the.de sired. product l-(5-methoxy-l ,3,4-thiadi a zo 2 yl)-3-ethyl 5 n propox y- 1 EXAMPLE"17"-: Iu N Preparatio'ii of ,3

Isocya riate Dimer A saturated solution o i "phosgene ml) is chargedinto :a glass equipped with a mechanicalstirrer. A slurry of 5-methylthio-2-amino-l,3,4-thiadiazole (45 grams) in ethyl acetate (300ml)is added to the reaction vessel and the resulting mixture stirred for aperiod cf about 16 hours, resulting in the formation of a precipitate.

The reaction mixture is then purged'with nitrogengas .benzene underreduced pressure to yield a solid product as the residue. The residue isthen recrystallized to yield the desired product the. dimethyl acetal of2-[1- propyl-3 5-methylthio- 1 ,3,4-thiadiazol2- yl)ureido]acetaldehyde.

EXAMPLE 1 9 Preparation of l'-( S-Methylthio-l ,3,4-thiadiazo1-2-yl)-3-propyl-5- hydroxy-1,3-imidazolidin-2-one The dimethylacetal of 2-['l-propyl-3 (5-methylthio- 1,3,4-thiadiazol-2-yl)ureidolacetaldehyde ('15 grams), water (400 ml) andhydrochloric acid (4' ml) are charged into a glass reaction vesselequipped with a mechanical stirrer, thermometer and reflux condenser.The reaction mixture is heatedat reflux for a period of about 15minutes. The reaction mixtureis' then filtered while hot and thefiltrate iscooled to form a precipitate. The precipitate is recovered byfiltration, is dried and is recrystallized to yield the clesired product l-(5- methylthio-l ,3,4-thiadiazol-2-yl )-3-propyl-5-hydroxy-1,3-imidazolidin -2-one. g I

EXAMPLE 20 1 7 Preparation of1-(5-Methylthio-l,3,4-thiadiazol-2-yl)-3-propyl 5- Imethoxy-IQ-imidazQIidin-Z one l-( S-Methylthiol ,3,4-thiadiazol-2-yl)-3,-propyl-5- hydroxy-l,Bdmidazolidin-Lone (7 grams) methyl alcohol,(50ml) andf toluenesulfonic ac id (0,2 grams) are charged ir1to.,a,glassreactionIvesselequipped.with a mechanical stirrer,thermometerand reflux condenser. The reaction mixtur e is thien heatedat reflux for aperiod of about 24: hours. After this time; the mixtu reis stripped of unreacted alcohol under reduced pressure in ethyl acetateI reaction vessel to yield a solid product. The solid product is thenrecrystallized to yield the' desired product b .1-(-

methylthiol ,3 ,4-thiadiazol-2-yl )-3 propyl-5-methoxy- 1,3-imidazolidin-2-one.

EXAMPLE 2';

Preparation of S-Methylsulfonyll ,4-thiadiazol-2-yl isocyanate DimerEXAMPLE 22 Preparation of the Dimethyl Acetal of 2-[ l-Methyl-3-(5-methylsulfonyl-1,3,4-thiadiazol-2- yl)ureido]acetaldehyde Amixture of S-methylsulfonyl-l,3,4-thiadiaZol-2-yl isocyanate dimer (0.05mole), the dimethyl acetal of 2-methylaniinoacetaldehyde (0.1 mole) andbenzene (60' ml) are charged into a glass reaction vessel equipped witha mechanical stirrer and reflux condenser. The reaction mixture isheated at reflux for a period of about minutes. After this time themixture is stripped of benzene under reduced pressure to yield a solidproduct as the residue. The residue is then recrystallized to yield thedesired product dimethyl acetal of 2-[ l-methyl-3-(5-methylsulfonyl-1,3,4-thiadiazol-2- yl )ureido1acetaldehyde.

EXAMPLE 2'3 p Preparation ofl-(5-Methylsulfonyl-1,3,4-thiadiazol-2-yl)-3-methyl-5- hydroxy-l,3-imidazolidin-2-one The dimethyl acetal of 2-[ l-methyl-3-(5-methylsulfonyl-1,3,4-thiadiazol-2- yl)ureido]acetaldehyde'(15 grams),water (400 ml) and hydrochloric acid (4 ml) are charged into' a glassreaction vessel equipped with a mechanical stirrer, thermometer andreflux condenser. The reaction mixture is heated at reflux for a periodof about 15 minutes. The reaction mixture is then filtered while hot andthefiltrate iscooled to form a precipitate. The precipitate is recoveredby filtration, isdried and is recrystallized to yield the desiredproduct l-(5-methylsulfon'yll,3',4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3- irnidazolidin-2-one. V

' EXAMPLE 24 Preparation of II-(S-Methylsulfonyl-1,3,4-thiadiazol-2-yl)-3 methyl-5- methoxy-l,3-imidaz0lidin-2-one 1- S-Methylsulfonyl- 1 ,3,4-thiadiazol-2-yl)-3-methyl- S-hydroxy-l,3-imidazolidin-2-one (.7 grams), methyl alcohol(50' ml) and'toluenesulfonic acid (0.2 grams) are charged into a glassreaction v'essel equipped with a mechanical stirrer, thermometer andreflux condenser. .The reaction mixture istheri heated at reflux for aperiod of about 24 hours. After this time the mixture is stripped ofunreacted alcohol under reduced pressure .toyield a solid product. Thesolid product is then recrystallized to yield the desired product 1-(5-methylsulfonyl- 1 ,3,4-thiadiazol-2-yl )-3-methyl-5- methoxyl,3'-imidazolidin-2-one.

EXAMPLE 25 Preparation of S-Methylsulfinyl-1,3,4-thiadiazol-2-ylIsocyanate Dimer A saturated solution of phosgene in ethyl acetate (100ml) is charged into a glass reaction vessel equipped with amechanical-stirrer. A slurry of 5-methylsulfinyl-Z-amino-1,3,4-thiadiaz0le (50 grams) in ethyl acetate(300 ml) is added to the reaction vessel and the resulting mixture isstirred for a period of about 1.6 hours, resulting in the formation of aprecipitate.

1 The reaction mixture is then purged with nitrogen gas to removeunreacted phosgene. The purged mixture is then filtered to recover theprecipitate. The precipitate A is then recrystallized to yield thedesired product.5-

rnethylsulfinyll ,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 26 0 Preparation of the Dimethyl Acetal of 2-[ l-Methyl-3-(5-methylsulfinyll ,3,4-thiadiazol-2- -yl)ureido]acetaldehyde A mixtureof S-methylsulfinyl-l,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole),the dimethyl acetal of 2-methylaminoacetaldehyde (0.1 -mole) and benzene(60 ml) are charged into a glass reaction vessel equipped with amechanical stirrer and reflux condenser.jThe reaction mixture is heatedatreflux fora period of about 15 minutes. After this time the mixture isstripped of benzene under reduced pressure to yield .a solid product asthe residue. The residue is then recrystallizedto yield the desiredproduct the dimethyl acetal of 2-[ 1%methyl 3-(S-methylsulfinyl-1,3,4-thiadiazol-Z-yl)ureido]acetaldehyde.

EXAMPLE 27 Preparation of1-(5-Methylsulfinyl-l,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3-imidazolidin-2-one The dimethyl acetal of 2-[ 1-methyl-3-(5- methylsulfinyll ,3,4-thiadiazol-2- yl)ureido]acetaldehyde (l5 grams),water (400 ml) .and hydrochloric acid (4 ml) are charged into a glassreaction vessel equipped with a mechanical stirrer,

' thermometer and reflux condenser. The reaction mixture '.is heated atreflux for a period of about 15 minut'es. The reaction mixture is thenfiltered while hot and the filtrate is cooled to form a precipitate. Theprecipitate is recovered by filtration, is dried and is recrystallizedto yield the desired product 1-(5-methylsulfinyl- 1 ,3,4-thiadiazol-2-yl)-3-methyl-5-hydroxy-1,3- imidaz'olidin-2-one.

EXAMPLE 28 Preparation of l-(5-Methylsulfinyll,3,4-thiadiazol-2yl)-3-methyl-5- methoxy-1,3-imidazolidin-2-onel-(.5.-Methylsulfinyl- 1 ,3,4-thiadiazol-2-yl )-3-methyl- 5-hydroxyl ,3imidazolidin-2-one (7 grams), methyl alcohol( ml and toluenesulfonicacid (0.2 grams) are charged into a glass reaction vessel equipped witha mechanical stirrer, thermometer and reflux condenser. The reactionmixture is'then heated at reflux for a period of about 24 hours. Afterthis time the mixture is stripped of unreacted alcohol under reducedpressure to yield a solid product. The solid product is thenrecrystallized to yield the desired product l-(- methylsulfinyl-l,3,4-thiadiazol-2-yl )-3-methyl-5- methoxyl ,3-imidazolidin-2-one.

EXAMPLE 29 Preparation of S-Cyclobutyll ,3,4-thiadiazol-2-yl lsocyanateDimer A saturated solution of phosgene in ethyl acetate I (100 ml) ischarged into a glass reaction vessel equipped with a mechanical stirrer.A slurry of 5- cyclobutyl-Z-amino-1,3,4-thiadiazole (50 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product 5- cyclobutyll,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 30 Prepartion of the Dimethyl Acetal of 2-[ l-Propyl-3-(S-cyclobutyl-l ,3,4-thiadiazol-2- yl)ureido]acetaldehyde EXAMPLE 3 lPreparation of l-( S-Cyclobutyll ,3,4-thiadiazol-2-yl )-3-propyl-5-hydroxy-l ,3-imidazolidin-2-one The dimethyl acetal of 2-[l-propyl-3-(5-cyclobutyl- 1.3 ,4-thiadiazol-2-yl)-ureidolacetaldehydegrams), water (400 ml) and hydrochloric acid (4 ml) are charged into aglass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of about 15 minutes. The reaction mixture is then filtered whilehot and the filtrate is cooled to form a precipitate. The precipitate isrecovered by filtration, is dried and is recrystallized to yield thedesired product 1-(5- cyclobutyll ,3 ,4-thiadiazol-2-yl)-3-propyl-5-hydroxy- 1,3-imidazolidin-2-one.

EXAMPLE 32 Preparation of l-( S-Cyclobutyl-l 3 ,4-thiadiazol-2-yl)-3-methyl-5- methoxyl ,3-imidazolidin-2-one 1-( S-Cyclobutyl-l ,3,4thiadiazol-2-yl)-3-methyl-5- hydroxy-l,3-imidazolidin-2-one (7 grams),methyl alcohol (50 ml) and toluenesulfonic acid (0.2 grams) are chargedinto a 'glass reaction vessel equipped with a mechanical stirrer,thermometer and reflux condenser. The reaction mixture is then heated atreflux for a period of about 24 hours. After this time the mixture isstripped of unreacted alcohol under reduced pressure to yield a solidproduct. The solid product is then re crystallized to yield the desiredproductl-(5- cyclobutyl- 1,3 ,4-thiadiazol-2-yl )-3-methyl-5-methoxyl,3-imidazolidin-2-one.

EXAMPLE 33 Preparation of 5-Cyclohexyl-l ,3,4-thiadiazol-2-yl lsocyanateDimer A saturated solution of phosgene in ethyl acetate ('100 ml) ischarged into a glass reaction vessel equipped with a mechanical stirrer.A slurry of 5- cyclohexyl-2-amino-l,3,4-thiadiazole (50 grams) in ethylacetate (300 ml) is added to the reaction vessel and the resultingmixture is stirred for a period of about 16 hours, resulting in theformation of a precipitate. The reaction mixture is then purged withnitrogen gas to remove unreacted phosgene. The purged mixture is thenfiltered to recover the precipitate. The precipitate is thenrecrystallized to yield the desired product 5- cyclohexyl- 1 ,3,4-thiadiazol-2-yl isocyanate dimer.

EXAMPLE 34 Preparation of the Dirriethyl Acetal of 2-[ l-Methyl-3-(5-cyclohexyll ,3 ,4-thiadiazol-2- yl)ureido]acetaldehyde A mixture of5-cyclohexyl-l ,3,4-thiadiazol-2-yl isocyanate dimer (0.05 mole), thedimethyl acetal of 2- methylaminoacetaldehyde (0.1 mole) and benzene (60ml) are charged into a glass reaction vessel equipped with a mechanicalstirrer'and reflux condenser. The re- EXAMPLE 35 Preparation of l-(S-Cyclohexyl-l ,3 ,4-thiadiazol-2-yl )-3-methyl-5-hydroxy-1,3-imidazolidin-2-one The dimethyl acetal of 2-[l-methyl-3-(S-cyclohexyll,3,4-thiadiazol-2-yl)ureido1acetaldehyde 15grams), water (400 ml) and hydrochloric acid (4 ml) are charged into aglass reaction vessel equipped with a mechanical stirrer, thermometerand reflux condenser. The reaction mixture is heated at reflux for aperiod of EXAMPLE 36 u Preparation of 1- (5-Cyclohexyll ,3,4-thiadiazol-2-yl )-3-methyl-5- methoxyl ,3-imidazolin-2-one hydroxy-l,3 imidazolidin-2 one (7 grams),'methyl alcohol (50 ml) and toluenesulfonic acid (0.2 grams) are charged into a glass reactionvessel'equipped with a mechanical stirrer, thermometer and refluxcondenser. The reaction mixture is then heated at reflux for a period ofabout 24 hours. After this time the mixture is stripped of unreactedalcohol under reduced pressure to yield a solid product. The solidproduct is then recrystallized to yield the desired product l-(-cyclohexyll ,3 ,4-thiadiazol-2-yl )-3-methyl-5-methoxy-1,3-imidazolidin-2-one.

Additional exemplary compounds within the scope of this invention whichcan be prepared by the procedures detailed in the foregoing examples arel-(5-ethyl-1,3,4- thiadiazol- 2-yl)-3-methyl-5-methoxy-l,3-imidazolin-2-one, l-(S-propyl-l ,3,4-thiadiazol-2-yl)-3-butyl-5- butoxy-l,3-imidazolidin-2-one, l-( 5-hexyl-l ,3 ,4- thiadiazol-2-yl)-3-pentyl-5-pentyloxy-l ,3-imidazolidin- 2-one, l-( 5-allyll,3,4-thiadiazol-2-yl )-3-hexyl-5- hexyloxyl ,3-imidazolidin-2-one, l-(5-pent-3-enyll ,3 ,4-thiadiazol-2-yl )-3-methyl-5-methoxyl ,3-imidazolidin-Z-one, l-( 5-hex-4-enyl- 1 ,3,4-thiadiazol-2- yl)-3-methyl-5-methoxy- 1 ,3-imidazolidin-2-one, 1-(5- chloromethyll ,3,4-thiadiazol-2-yl )-3-methyl-5- methoxy-l ,3-imidazolidin-2-one, 1-(S-ethoxy-l ,3,4- thiadiazol-Z-yl )-3-methyl-5-methoxy-l ,3-imidazolidin-2-one, l-( S-propoxyl ,3 ,4-thiadiazol-2-yl )-3-methyl-5- methoxyl,3-imidazolidin-2-one, l-( 5-hexyloxy-l ,3,4- thiadiazol-2-yl)-3-methyl-5-methoxy-l ,3-imidazolidin- 2-one, l-( S-ethylthiol,3,4-thiadiazol-2-yl)-3-methyl- S-methoxyl ,3-imidazolidin-2-one, l-(S-propylthiol ,3 ,4-thiadiazol-2-yl)-3-methyl-5-methoxy-l ,3-imidazolidin- 2-one, l-(5-butylthio-1,3,4-thiadiazol-2-yl)-3-methyl-5-methoxy-l,3-imidazolidin-2-one, l-(5- hexylthiol,3,4-thiadiazol-2-yl)-3-methyl-5-methoxyl,3-imidazolidin-2-one, l-(S-ethylsulfinyll ,3 ,4- thiadiazol-2-yl )-3-methyl-5-methoxy'-l,3-imidazolidin- 2-one, l-( 5-propylsulfmyll ,3,4-thiadiazol-2-yl )-3-methyl-S-methoxyl ,3-imidazolidin-2-one, 1-( 5- hexylsulfinyll,3,4-thiadiazol-2-yl )-3-methyl-5- methoxyl ,3-imidazolidin-2-one, l-(5-ethylsulfonyl- 1,3 ,4-thiadiazol-2-y] )-3-methyl-5-methoxyl ,3-imidazolidin-Z-one, l-( S-butylsulfonyl-l ,3 ,4- thiadiazol-Z-yl)-3-methyl-5-methoxy-l ,3-imidazolidin- 2-one, l-( S-hexylsulfonyll,3,4-thiadiazol-2-yl)-3- methyl-S-methoxy-l ,3-imidazolidin-2-one, 1-(5- cyclopropyl-l ,3,4-thiadiazol-2-yl )-3-methyl-5- methoxyl,3-imidazolidin-2-one,l-(5-cyclopentyll,3,4-thiadiazol-2-yl)-3-methyl-5-methoxy-1,3-imidazolidin-Z-one, l-(5-cycloheptyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-methoxy- 1,3-imidazolidin-2-one, l- [5-(3-methylcyclohexyl)- l ,3,4-thiadiazol-2-yl1-3- methyl-S-methoxy-l,3-imidazolidin-2-one, l-[ 5-( 3- ethylcyclohexyl l ,3,4-thiadiazol-2-yl]-3-methyl-5- methoxy-1.3-imidazolidin-2-one, 1-[5-(4- hexylcyclohexyl)-1 ,3,4-thiadiazol-2-yl l-3-methyl-5- methoxy-1,3-imidazolidin-2-one, l-[5-( 2- methoxycyclohexyl )-l ,3 ,4-thiadiazol-2-yl l-3-methyl-5-methoxy-l ,3-imidazolidin-2-one, l-[ 5-( 3- ethoxycyclohexyl)-l,3,4-thiadiazol-2-yl]-3-methyl-5- methoxyl ,3-imidazolidin-2-one, l-[5-(4- hexyloxycyclohexyl )-l ,3,4-thiadiazol-2-yl ]-3-methyl-S-methoxy-1,3-imidazolidin-2-one, l-[5-(4- chlorocyclohexyl )-l,3,4-thiadiazol-2-yl]-3-methyl-5- methoxyl ,3-imidazolidin-2-one, l-[5-(4- bromocyclohexyl 1 ,3,4-thiadiazol-2-yl ]-3-methyl-5- methoxyl,3-imidazolidin-2-one, l-[ 5-( 4- fluorocyclohexyl l,3,4-thiadiazol-2-yl ]-3-methyl-5- methoxy-l,3-imidazolidin-2-one,l-(5-t-butyl-l,3,4 -thiadiazol-Z-yl)-3-methyl-5-isopropoxy-1,3-imidazolidin- 2-one, I-(S-t-butyl- 1 ,3,4-thiadiazol-2-yl )-3-methyl-5- octyloxy-l ,3-imidazolidin-2-one, l-( S-t-butyll ,3,4-thiadiazol-2-yl)-3-methyl-5 -decyloxy-1 ,3- imidazolidin-Z-one, l-(S-t-butyll ,3 ,4-thiadiazol-2-yl 3-methyl-5-octadecyloxy- 1,3-imidazolidin-2-one, l-( 5- t-butyl- 1 ,3,4-thiadiazol-2-yl)-3-methyl-5-eicosyloxyl ,3-imidazolidin-2-one, 1-( S-t-butyll ,3,4-thiadiazol-2- yl )-3-methyl-5-( 2-ethylhexyloxy)-l ,3-imidazolidin-2-one.

For practical use as herbicides the compounds of this invention aregenerally incorporated into herbicidal compositions which comprise aninert carrier and a herbicidally toxic amount of such a compound. Suchherbicidal compositions, which can also be called formulations, enablethe active compound to be applied conveniently to the site of the weedinfestation in any desired quantity. These compositions can be solidssuch as dusts, granules, or wettable powders, or they can be liquidssuch as solutions, aerosols, or emulsifiable concentrates.

For example, dusts can be prepared by grinding ,and blending the activecompound with a solid inert carrier such as the talcs, clays, silicas,pyrophyllite, and the like. Granular formulations can be prepared byimpregnating the compound, usually dissolved in a suitable solvent, ontoand into granulated carriers such as the attapulgites or thevermiculites, usually of a particle size range of from about 0.3 to 1.5mm. Wettable powders, which can be dispersed in water or oil to anydesired concentration of the active compound, can be prepared byincorporating wetting agents into concentrated dust compositions.

In some cases the active compounds are sufficiently soluble in commonorganic solvents such as kerosene or xylene so that they can be useddirectly as solutions in these solvents. Frequently, solutions ofherbicides can be dispersed under super-atmospheric pressure asaerosols. However, preferred liquid herbicidal compositions areemulsifiable concentrates, which comprise an active compound accordingto this invention and as the inert carrier, a,s.olvent and anemulsifier. Such emulsifiable concentrates can be extended with waterand/or oil to any desired concentration of active compound forapplication as sprays to the site of the weed infestation. Theemulsifiers most commonly used in these concentrates are nonionic ormixtures of nonionic with anionic surface-active agents. With the use ofsome emulsifier systems an inverted emulsion (water in oil) can beprepared for direct application to weed infestations.

A typical herbicidal composition according to this invention isillustrated by the following example, in which the quantities are inparts by weight.

EXAMPLE 37 Preparation of a Dust Product of Example 4 Powdered Talc Thecompounds of this invention can be applied as herbicides in any mannerrecognized by the art. ,One method for the control of weeds comprisescontacting the locus of said weeds with a herbicidal compositioncomprising an inert carrier and as an essential active ingredient, in aquantity which is herbicidally toxic to said weeds, a compound of thepresent invention. The concentration of the new compounds of thisinvention in the herbicidal compositions will vary greatly with the typeof formulation and the purpose for which it is designed, but generallythe herbicidal compositions will comprise from about 0.05 to about 95percent by weight of the active compounds of this invention. In apreferred embodiment of this invention, the herbicidal compositions willcomprise from about to about 75 percent by weight of the activecompound. The compositions can also comprise such additional substancesas other pesticides, such as insecticides, nematocides, fungicides, andthe like; stabilizers, spreaders, deactivators, adhesives, stickers,fertilizers, activators, synergists, and the like.

The compounds of the present invention are also useful when combinedwith other herbicides and/or defoliants, dessicants, growth inhibitors,and the like in the herbicidal compositions hertofore described. Theseother materials can comprise from about 5% to about 95% of the activeingredients in the herbicidal compositions. Use of combinations of theseother herbicides and/or defoliants, dessicants, etc, with the compoundsof the present invention provide herbicidal compositions which are moreeffective in controlling weeds and often provide results unattainablewith separate compositions of the individual herbicides. The otherherbicides, defoliants, dessicants and plant growth inhibitors, withwhich the compounds of this invention can be used inthe herbicidalcompositions to control weeds, can include chlorophenoxy herbicides suchas 2,4-D, 2,4,5-T, MCPA, MCPB, alachlor, 4(2,4-DB), 2,4-DEB, 4-CPB,4-CPA, 4-CPP, 2,4,5-TB, 2,4,5-TES, 3,4-DA, silvex and the like;carbamate herbicides such as lPC, CIPC, swep, barban, BCPC, CEPC, CPPC,and

the like; thiocarbamate and dithiocarbamate herbicides such as CDEC,metham sodium, EPTC, diallate, PEBC, perbulate, vernolate and the like;substituted urea herbicides such as norea, siduron, dichloral urea,chloroxuron, cycluron, fenuron, monuron, monuron TCA, diuron,linuron,-monolinuron, neburon, buturon, trimeturon and the like;symmetrical triazine herbicides such as simazine, chlorazine, atraone,desmetryne, norazine, ipazine, prometryn, atazine, trietazine, simetone,

prometone, propazine, ametryne and the like; chlodichlobenil, DPA,diphenamid, dipropalin, trifluralin, solan, dicryl, merphos, MP A, DSMA,MSMA, potassium azide, acrole in, bene fin, bensulfide, AMsbromacil,2;(,3, lfdichlorophenyl)-4-methyll ,2,4- oxadiazolidine-B,5 dione,bromoxynil, \cacodylic acid, CMA, CPMF, cypromid,,=DCB,;DCPA, dichlone,diphenatril, DMTITT, D-NAR EBER-EXDHCA, ioxynil, IPX, isocil, potassiumjya'nate', MAA, MAMA, MCPES, MCPP, MH, molinate; NPA, OCH, paraguat,PCP, picloram, DPA, PCA, pyrichlor, sesone, terbacil, terbutol, TCBA,brominil, CP-50144, H-l76-l, H-732, M-290l planavin, sodium tetraborate,calcium cyanamid, DEF, ethylxanthogen disulfide, sindone, sindon e B,propanil and the like. I i

Such herbicides can also be used in the methods and compositions of thisinvention in the form of their salts, esters, amides, and otherderivatives whenever applicable to the particularparent compounds.

Weeds are undesirable plants growing where they are not wanted, havingno economic value, and interfering with the production of cultivatedcrops, with the growing of ornamental plants, or with the welfare oflivestock. Many types of weeds are known, including annuals such aspigweed, lambsquarters, foxtail, crabgrass, wild mustard, fieldpennycress, ryegrass, goose-grass, chickweed, wild oats, velvetleaf,purslane, barnyard grass, smartweed, knotweed, cocklebur, wildbuckwheat, kochia, medic, corn cockle, ragweed, sowthistle, coffeeweed,croton, cuphea, dodder, fumitory, ground-sel, hemp nettle, knawel,spurge, spurry, emex, jungle rice, pondweed, dog fennel, carpetweed,morning glory, bedstraw, ducksalad, naiad, cheatgrass, fall panicum,jimsonweed, witchgrass, switch grass, watergrass, teaweed, wild turnipand sprangletop; biennials such as wild carrot, matricaria, wild barley,campion,

chamomile, burdock, mullein, roundleaved mallow,-

bull thistle, hounds-tongue, moth mullein and purple star thistle; orperennials such as white cockle, perennial ryegrass, quackgrass, Johnsongrass, Canada thistle, hedge bindweed, Bermuda grass, sheep sorrel,curly dock, nutgrass, field chickweed, dandelion, campanula, fieldbindweed, Russian knapweed, mesquite, toadflax, yarrow, aster, gromwell,horsetail, ironweed, sesbania, bulrush, cattail, winter-Cress,horsenettle, nutsedge, milkweed and sicklepod'. v H

Similarly, such weeds can be classified as broadleaf or grassy weeds. Itis economically desirable to control the growth of such weeds withoutdamaging beneficial plants or livestock.

The new compounds of this invention are particularly valuable for weedcontrol because they are toxic to many species and groups of weeds whilethey are relatively non-toxic to many beneficial plants. The exactamount of compound required will depend on a variety of factors,including the hardiness of the particular weed species, weather, type ofsoil, method of application, thekind of beneficial plants in the samearea, and the like. Thus, while the application of up, to only about oneor twoounces of active compound per acre maybe sufficient for goodcontrol of a light infestation of weeds growing under adverse;conditions, the application of 10 pounds or more oflan active compoundper acre may be required for good control ofa dense infestation of hardyperennialweeds growing. under favorable conditions. 1 f

The herbicidal toxicity-of theinew compounds of this invention canbe'illustrated bymany of theestablished testing techniques known to theart, such as preand post-emergence testing.

The herbicidal activity of the compounds of this invention wasdemonstrated by experiments carried out for the pre-emergence control ofa variety of weeds. In these experiments small plastic greenhouse potsfilled with dry soil were seeded with the various weed seeds.Twenty-four hours or less after seeding the pots were sprayed with wateruntil the soil was wet and the test compounds formulated as aqueousemulsions of acetone solutions containing emulsificrs were sprayed atthe indicated concentrations on the surface of the soil.

After spraying, the soil containers were placed in the greenhouse andprovided with supplementary heat as required and daily or more frequentwatering. The plants were maintained under these conditions for a periodof from 15 to 21 days, at which time the condition of the plants and thedegree of injury to the plants was rated on a scale of from O to 10, asfollows: no injury, 1,2 slight injury, 3,4 moderate injury, 5,6moderately severe injury, 7,8,9 severe injury and death. Theeffectiveness of these compounds is demonstrated by the data in Table I.

TABLE I lnjury Rating Product of Example 8 Concentration (lbs/acre) Theherbicidal activity of the compounds of this invention was alsodemonstrated by experiments carried out for the post-emergence controlof a variety of weeds. In these experiments the compounds to be testedwere formulated as aqueous emulsions and sprayed at the indicated dosageon the foliage of the weeds that have attained a prescribed size. Afterspraying the plants were placed in agreenhouse and watered daily or morefrequently. Water was not applied to the foliage of the treated plants.The severity of the injury was determined 10 to days after treatment andwas rated on the scale of from O to 10 heretofore described. Theeffectiveness of these compounds is demonstrated by the data in TableII.

18 TABLE II Injury Rating Product of Example 8 Concentration (lbs/acre)wherein R is selected from the group consisting of lower alkyl, loweralkenyl, lower chloroalkyl, trifluoromethyl, lower alkoxy, loweralkylthio, lower alkylsulfonyl, lower alkylsulfinyl and cycloalkyl offrom 3 to 7 carbon atoms optionally substituted with from 1 to 2substituents selected from the group consisting of lower alkyl, loweralkoxy, chlorine, bromine and fluorine; R is lower alkyl; and R is analkyl group of up to 20 carbon atoms.

2. The compound of claim 1, I-(S-trifluoromethyl- 1,3,4-thiadiazol-2-yl)-3-methyl-5-methoxy-l ,3- imidazolidin-Z-one.

3. The compound of claim 1, l-(5-t-butyl-1,3,4- thiadiazol-Z-yl)-3-methyl-5-methoxy-1 ,3-imidazolidin- Z-one.

4. The compound of claim 1, l-(5-methyl-l,3,4- thiadiazol-2-yl)-3-methyl-5-ethoxy-l ,3-imidazolidine- 2-one.

5. The compound of claim 1, l-(5-methoxy-l,3,4- thiadiazol-Z-yl)-3-ethyl-5-n-propoxyl ,3-imidazolidin- 2-one.

6. The compound of claim 1, l-(5-methylthio-l,3,4- thiadiazol-2-yl)-3-propyl-5-methoxyl ,3-imidazolidin- 2-one.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 13,901,905

DATED I August 26, 1975 INVENTOR 1 John Krenzer it is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In column 1, formula II, appearing as I T? T R1 C C N N R2 S C ll 0should be it 'tt T T R c c N N R S C ll 0 Signed and Stealcd this thirdDay Of February 1976 [SEAL] Arrest:

' RUTH c. MASON C.MARSHALL DANN Arresting Officer Commissioner ofPatentsand Trademarks

1.A COMPOUND OF THE FORMULA
 2. The compound of claim 1,1-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-methoxy-1,3-imidazolidin-2-one.
 3. The compound of claim 1,1-(5-t-butyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-methoxy-1,3-imidazolidin-2-one.
 4. The compound of claim 1,1-(5-methyl-1,3,4-thiadiazol-2-yl)-3-methyl-5-ethoxy-1,3-imidazolidine-2-one.
 5. The compound of claim 1,1-(5-methoxy-1,3,4-thiadiazol-2-yl)-3-ethyl-5-n-propoxy-1,3-imidazolidin-2-one.
 6. The compound of claim 1,1-(5-methylthio-1,3,4-thiadiazol-2-yl)-3-propyl-5-methoxy-1,3-imidazolidin-2-one.